The disclosure relates to beverage brewing systems and in particular brewing systems which use a charge of brewing substance for use in pressurized brewing. Such pressurized brewing is often referred to as “espresso” brewing. Espresso brewing uses a relatively small charge of relatively finely ground coffee or other brewing substance for use in a confined brewing chamber. The brewing substance is compacted to a desired degree and then infused with pressurized water. Compaction of the brewing substance and infusion with the pressurized brewing water requires a sealed brewing chamber to facilitate proper brewing.
The beverage product produced in an espresso brewing process is referred to as “espresso.” Espresso tends to be a thicker beverage compared to drip, French press, cone, or other unpressurized brewing processes. Espresso tends to have a higher percentage of solubles and particulate matter and tends to be relatively viscous or “syrupy.” A variety of espresso brewing machines are available ranging from manual, semi-automatic, to fully automatic. In a manual process an operator grinds a quantity of coffee beans for use in the process. The ground coffee is loaded into a holder device often referred to as a “portafilter.” The portafilter is attached to a pressurized water dispensing head of the brewer. In this manner the ground coffee is contained in a closed, sealed space for brewing. The brewer is activated to controllably deliver pressurized brewing water to the coffee contained in the portafilter. The operator controls the machine for a selected period of time to produce a quantity of espresso beverage.
Fully automatic machines may include a control interface which allows a user to select a type of bean, quantity of espresso to be produced, and perhaps other characteristics. The fully automatic machine includes bean hoppers which may automatically deliver beans to a grinder and then dispense the ground coffee into a brewing chamber. Infusion with heated, pressurized water is automatically controlled by the machine after activation by the operator. At the conclusion of the brewing process a puck of spent, drained but moist, brewing substance is automatically removed from the brewing chamber and passed to a waste collection container for subsequent removal.
In some situations it may be useful to provide an alternative structure for brewing beverage. The alternative structure may be of a larger volume or may include other enhancements. As such it may be desirable to provide a modular assembly which allows the extraction assembly to be removed from one brewer and replaced with a different extraction assembly.
For example, it may be beneficial to initially place a brewer which satisfies various criteria including cost, production volume and reliability. At some point during the life of the system the extraction assembly could be removed and replaced with the extraction assembly which can be mounted in the same position of the machine and coupled to the same water, electrical or other connections. In other words, the new extraction assembly can be substituted for the prior extraction assembly. The prior assembly might be removed for repair purposes, or in order to upgrade the machine.
It may also be desirable to provide a brewer which includes a heating element in close proximity to a chamber which receives grounds for brewing. In this regard, heat can be brought directly to the area in which the coffee is brewed to help maintain a more consistent, tighter tolerance temperature and faster recovery between brew cycles. Temperature affects extraction process and having a preheated brew chamber helps in optimizing extraction process.
Also, it may be desirable to provide various parts that are replaceable, such as wear parts. In this regard, while it is routine to replace items such as gaskets and bushings, it would be desirable to provide a replaceable structure for the brew chamber itself so that the chamber may be removed since it can be a wear part as a result of piston operation against the chamber.